Obesity is a global epidemic, affecting people of all ages and socioeconomic levels. Being overweight or obese puts people at risk for serious health problems. It also exposes them to profound stigmatization and discrimination across a wide variety of domains. Experiencing racial and ethnic discrimination has been linked to poorer mental and physical health, including cardiovascular disease, hypertension, blood pressure reactivity, and depression. The effects of experiencing weight-based stigmatization (WS) on health, however, have been largely ignored. The proposed research addresses the psychological, behavioral, and biological effects on overweight men and women of experiencing or anticipating WS. We propose that WS is stressful and triggers a cascade of negative emotions, cognitions and biological responses that can damage mental and physical health. We also propose that experiencing or anticipating WS impairs health by activating processes that contribute to weight gain among those who are or perceive themselves to be overweight. These include increasing stress-related eating and reducing self-control capacity essential for regulating diet and exercise. We propose that WS also increases motivation and intentions to avoid stigma by losing weight while simultaneously decreasing the capacity to do so via the processes described above. This further exacerbates threat and can lead the overweight to engage in stigma-avoidance behaviors with negative health implications, such as avoiding exercise, or engaging in unhealthy behaviors to lose weight. We propose to conduct 4 experiments to test these hypotheses. Our aims are to demonstrate that for individuals who are overweight, social contexts that activate concerns about WS, including exposure to public health messages about the obesity epidemic: 1) are stressful, as indexed by increased blood pressure, cortisol reactivity, emotions, and activated stereotypes, 2) decrease self-regulatory capacity, as indexed by poorer performance on cognitive tasks requiring self-control and by reduced capacity of people who are overweight to resist consuming fattening food, and 3) increase motivation and intention to avoid stigma by attempting to lose weight, while decreasing individuals' capacity to do so, thus contributing to unhealthy eating behaviors and avoidance of exercise. We also propose to test three potential moderators of the above effects as well as several mediators of these effects. In addition, we will examine the downstream consequences of eating in response to WS. Collectively, these experiments will provide a better understanding of the psychological, physiological, and behavioral effects of weight stigma, including increased risk for cardiovascular disease, depression, and weight gain, and how these effects may be mitigated. Findings hold enormous potential to illuminate psychological processes that may contribute to, and potentially reduce, obesity and will have implications for the design of public campaigns to reduce the obesity epidemic.